How to Claim the Boiler Upgrade Scheme for Your Underfloor Heating Project (2026)
If you're planning to install wet underfloor heating, the Boiler Upgrade Scheme (BUS) can put up to £7,500 toward the cost of the heat pump that will power it — and wet UFH is, by design, the most efficient partner system for a heat pump.
This guide explains exactly how the scheme works, whether your property qualifies, what role your installer plays in claiming the grant, and how to stack BUS with other available funding to reduce the overall cost of your project.
What Is the Boiler Upgrade Scheme?
The Boiler Upgrade Scheme is a UK government grant programme administered by Ofgem. It provides upfront capital contributions to homeowners who replace fossil fuel heating systems with low-carbon alternatives:
| Heat Pump Type | Grant Amount |
|---|---|
| Air source heat pump (ASHP) | £7,500 |
| Ground source heat pump (GSHP) | £7,500 |
| Water source heat pump | £7,500 |
The grant is paid directly to your installer, who reduces their invoice by the grant amount. You pay the difference — the grant is not a rebate you claim after the fact.
Why Wet UFH and Heat Pumps Are the Ideal Combination
Heat pumps work most efficiently when generating heat at low flow temperatures — typically 35–45°C. Conventional radiators were designed for 70–80°C flow temperatures (gas boiler era), which forces a heat pump to work harder and use more electricity.
Wet underfloor heating, by contrast, operates at exactly the low flow temperatures heat pumps prefer. The larger surface area of a heated floor compensates for the lower temperature — your rooms reach the same comfort level while the heat pump runs at peak efficiency (typically 3–4 units of heat per unit of electricity consumed, or a COP of 3–4).
The practical result: a heat pump paired with wet UFH typically achieves 30–40% lower heating running costs compared to a gas boiler with radiators — and is eligible for the full £7,500 BUS grant.
Does Your Property Qualify for the BUS?
The scheme is available to properties in England and Wales. Scotland has its own separate scheme (Home Energy Scotland Heat Pump Grant, up to £9,000). Northern Ireland has separate funding routes.
To qualify, your property must:
- Be a residential property (not a new build — new builds have a separate route)
- Currently use fossil fuel heating (gas, oil, LPG, electric direct) — properties with existing heat pumps are not eligible
- Not have received a previous BUS grant
- Have a valid Energy Performance Certificate (EPC) on record
- Have sufficient insulation for heat pump efficiency (poorly insulated homes may need upgrades first)
Oil-heated properties are particularly well-suited for BUS funding. Replacing oil with a heat pump eliminates a costly fuel source (oil typically runs at 7–12p/kWh equivalent delivered), and BUS combined with ECO4 insulation grants can cover a substantial portion of total project costs.
Gas-heated properties also qualify. The government's push to decarbonise home heating means gas boiler owners are actively encouraged to switch, and the £7,500 grant applies equally.
The MCS Requirement — Why Your Installer Choice Is Critical
This is the single most important thing to understand about the BUS: the grant can only be claimed by an installer who holds MCS (Microgeneration Certification Scheme) accreditation for the heat pump technology being installed.
MCS is a quality assurance scheme for low-carbon technologies. An MCS-accredited installer has been independently assessed against technical standards and is registered on the MCS database at mcscertified.com. Only MCS-accredited installers can:
- Apply for a BUS voucher on your behalf via the Ofgem portal
- Install a heat pump that qualifies for the grant
- Provide the MCS certificate required by Ofgem to release payment
If you hire a non-MCS installer — even a very competent one — you will not be able to claim the BUS grant. There is no workaround.
For wet UFH specifically, your installer will typically also need:
- Gas Safe registration (if decommissioning your existing gas boiler)
- CIPHE or APHC membership (optional but reassuring for the wet UFH pipework)
- Relevant manufacturer training for the heat pump brand being installed
How the BUS Claim Process Works (Step by Step)
The good news: the homeowner's role in claiming the grant is minimal. Your MCS-accredited installer handles the application process.
Step 1 — Find an MCS-accredited installer Search mcscertified.com/find-an-installer or use our UFH installer directory to find local professionals. Confirm they hold MCS accreditation for air source or ground source heat pumps before progressing.
Step 2 — Get a heat loss survey and system quote A compliant BUS installation requires a proper heat loss calculation for your property. This is not optional — it's a technical requirement of MCS standards and ensures the heat pump is correctly sized. Expect to pay £200–£500 for a thorough survey, though many installers include this in their full project quote.
Step 3 — Installer applies for a BUS voucher Your MCS installer applies for a BUS voucher via the Ofgem portal before installation begins. The voucher is valid for 3 months. This is done entirely by the installer — you'll be asked to provide consent and property details.
Important for oil-heated properties: The voucher must be applied for before installation starts — not afterwards. This is not administrative formality. For households replacing oil heating (where fuel costs run highest and the financial case for switching is strongest), missing this step means forfeiting the full £7,500 regardless of how good the installation is. Agree the voucher application date with your installer as a firm milestone before any work begins.
Step 4 — Installation and commissioning The heat pump and wet UFH system are installed. For new UFH, allow 3–7 days of active installation plus 4–6 weeks for screed curing before floor coverings can be laid. The installer commissions the system (pressure tests, fills and balances the UFH circuit, sets flow temperatures).
Step 5 — MCS certificate issued Once commissioning is complete, your installer issues an MCS certificate confirming the installation meets scheme standards. This triggers Ofgem payment — the £7,500 is paid to the installer, reducing what you owe.
Stacking BUS with ECO4 Insulation Grants
The BUS grant covers the heat pump. But heat pump efficiency depends heavily on insulation — a poorly insulated home requires a larger, more expensive heat pump and has higher running costs.
The ECO4 scheme (Energy Company Obligation, phase 4) provides grants for insulation upgrades — loft insulation, cavity wall insulation, solid wall insulation, and floor insulation — to eligible households. ECO4 is means-tested (eligibility based on income and property EPC rating), and it is entirely separate from BUS.
For eligible properties, combining BUS + ECO4 can reduce the combined cost of insulation upgrades + heat pump + UFH installation by 50–100%.
Even if you don't qualify for ECO4, it's worth getting your EPC upgraded before the heat pump survey — better insulation directly reduces the size (and cost) of heat pump needed.
What Does a Full BUS-Funded Heat Pump + UFH Project Cost?
| Component | Typical Cost | BUS/ECO4 Contribution |
|---|---|---|
| Air source heat pump (supply + install) | £8,000–£15,000 | £7,500 BUS grant |
| Wet UFH (whole house, 3-bed, new build) | £6,500–£10,500 | — |
| Wet UFH (retrofit overlay, 3-bed) | £9,000–£15,000 | — |
| Insulation upgrades (if needed) | £2,000–£8,000 | ECO4 (if eligible) |
| Total (new build example) | £14,500–£25,500 | £7,500+ off |
After the BUS grant, a full heat pump + whole-house wet UFH installation in a new build or major renovation typically costs £7,000–£18,000 out of pocket — and will deliver significantly lower heating bills from day one.
Frequently Asked Questions
Can I claim the BUS grant if I'm only installing underfloor heating, not a heat pump? No. The BUS grant is specifically for the heat pump, not the UFH system itself. To benefit, you need to install both the heat pump and the wet UFH. However, the combined project cost is substantially offset by the grant.
What if my property has an existing heat pump? If you already have a heat pump, your property is not eligible for a new BUS grant for a replacement. The scheme is designed for first-time heat pump installations replacing fossil fuel heating.
Is there a minimum property insulation standard to qualify? There is no strict EPC threshold to qualify for BUS (unlike the previous RHI scheme), but MCS standards require the installer to check that the heat pump is appropriately sized for the property's heat loss. Very poorly insulated properties may need insulation work first to make the installation viable.
Can I use the BUS for a ground source heat pump? Yes — ground source heat pumps (GSHPs) receive the same £7,500 grant as ASHPs. GSHPs are more efficient (typically COP 3.5–5) but have higher upfront costs (£15,000–£35,000 installed). Combined with UFH, the running cost savings are excellent.
How long does the BUS application take? Voucher applications are typically processed within 1–5 working days. Your installer should apply well before the installation date to avoid delays.
Find an MCS-Certified Installer Near You
The critical first step is finding an MCS-accredited installer who can claim the BUS grant on your behalf and design a compliant heat pump + UFH system.
Browse our directory of verified UFH installers across the UK — and when you contact any installer, confirm their MCS accreditation number upfront.
- Find installers in London
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- Browse all locations
Or request free quotes from local installers and let us match you with MCS-accredited professionals in your area.